Method of erecting wall-form

ABSTRACT

A method of erecting wall forms of the type used to cast concrete walls in which a pair of form panels are first positioned in spaced, wall-defining relation to one another, tie rod assemblies are inserted transversely through the panels and attached thereto to hold the panels in spaced relation, external stud and waller bracing is subsequently erected on the outer sides of the panels, and the tie rod assemblies are then connected in force-transmitting relation to the bracing.

I United States Patent 1 [111 3,905,093

Williams Sept. 16, 1975 [54] METHOD OF ERECTING WALL-FORM 2,0l4,0809/1935 Colt 249/217 2 259 l [76] Inventor: Chester 1. Williams, 347Greenbriar, 3 52;; $132 S.E., Grand Rapids, 3:4 4: 7 9 9 9 [22] Filed:Jan. 18, 1973 3,614,052 10/1971 [2]] Appl- N 1 4, PrimaryExaminerCharlie T. Moon Related US. Application Data [62] Division ofSer. No. 59,466, July 30, I970, [57] ABSTRACT abandoned. A method oferecting wall forms of the type used to cast concrete walls in which apair of form panels are [52] U5. Cl. 29/526; 249/43; 249/217 fir p i iin p wall-defining relation to n [51] Int. Cl 823 19/00 another, i rod mli r n erted transversely [58] Field of Search 29/455, 452, 469, 526;hrough the panels and attached thereto to hold the 249/ 19], 217, 190,43, 42 panels in spaced relation, external stud and waller bracing issubsequently erected on the outer sides of [56] References Cited thepanels, and the tie rod assemblies are then con- UNTED STATES PATENTSnected in force-transmitting relation to the bracing.

2,002,526 5/1935 Colt 249/42 X 1 Claim, 10 Drawing Figures PATENTEU3,905,093

SHEET 1 [IF 2 mm mm 3 on mm 7 5 6 mm NW INVE/VTOR Chester I. Williams B)k ivy ATTORNEY METHOD OF ERECTING WALL-F This is a division ofapplication Ser. No. 59,466, filed July 30, 1970, and now abandoned.

BACKGROUND OF THE INVENTION The construction of concrete walls normallyinvolves the pouring of fresh concrete in the space between parallelpanels. The liquid pressure generated by the concrete is approximately a160 pounds'per square foot at the bottom of the pour for every foot ofpoured height. The resulting forcesconfined by the form panels are veryhigh, and require the presence of either cross-tie systems securing oneform with respect to the other, or extensive exterior bracing. Where thecross-tie system is used, the exterior bracing need only be ofsufficient strength to maintain the vertical orientation of the forms,as the forces generated by the poured concrete are transferred from oneform to the other, and thus confined within the form system.

One of the common methods of cross-tying forms involves the use of a tierod extending partially across the space between the forms, with theopposite ends of this tie rod in threadedengagement with boltstraversing the forms and secured to them. After the forms have beenremoved from the set concrete, the tie rod remains embedded in theresulting wall. It has been common practice to provide the bolts with aconical end positioned in the space between the form panels, resultingin the formation of a similarly-shaped conical depression in theconcrete after the bolt has been removed. This arrangement obviouslyremoves the necessity for having the tie rod extend beyond the face ofthe poured wall. The outer end of the bolt is usually engaged by a nutbearing on some sort of bracket capable of transferring the forcesinvolved over to beams extending across parallel stiffeners placedagainst the outside of the form panel.

This arrangement easily prevents separation of the form panels, but aproblem remains as to how to secure the proper spacing of the panelsduring the initial placement preparatory to pouring the concrete.Efi'icieney in erecting these form systems requires that it be possibleto tighten the exterior nuts down to some positive established spacingabutment so that the thickness of the poured wall can be controlledwithout the necessity of making measurements at each point where the tiesystem is adjusted. Arrangements have been devised for positivelyinterrelating the position of the bolt with respectto theform structureso that the form cannot move either way, once the'bolts are engaged withthe tie rod. The present invention relates to this type of tie system,and'provides an assembly of components that is easier to install thananything known to applicant, and. involves components that are easilymanufactured of relatively inexpensive materials.

SUMMARY OF THE, INVENTION The wall-form tie system provided by thisinvention utilizes'a tubular cone member with its conical portiondisposed normally on the inside of the form panel with whichit-i'sassociated. A shank extendingfrom the cone member traverses a suitablehole in the form panel, and the securing bolt traverses both this shankand the cone section. The cone member is secured with 'respectto theform panel preferably either by threaded interengagement between theshank and'the material of the form panel, or by the addition of anut inthreaded engagement with the shank and bearing against the outside ofthe form panel. The diameter of the shank is sufficiently less than thatof the major diameter of the conical portion to provide a shoulderbearing against the inside of the form panel. The axial position of thebolt Within the cone member is preferably established by a cross pinintersecting both the shank and the bolt. The stress-transfer nut at theouter end of the bolt can thus be tightened against the bracket bearing,against the waler beams supporting the form without altering theposition of the bolt in a direction transverse to the form panel. Propertightening can thus be established without concern for continuallyhaving to measure the space between the form panels, or place temporarycontrol abutments between the form panels for the adjustment. It ispreferable to utilize a system for controlling the degree of. threadedinterengagement between the inner tie rod and the bolts by an abutmentarrangement of the type described and claimed in my application for US.Pat. Ser. No. 751,313, now abandoned.

The removal of the forms after the concrete has set will carry the conemembers along with the form panel. The resulting conical recesses in theconcrete wall can either be filled with grout, or with a molded plug of.some convenient material. Occasionally, the conical recesses are left inthe wall as a decorative measure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional elevation of awall-form system in condition to receive the poured concrete.

FIG. 2 is a sectional elevation of a modified form of the invention, inwhich the cone members are in threaded interengagement with the materialof the form panels.

FIG. 3'is an axial section of the cone member shown in the FIG. 1assembly, on an enlarged scale.

FIG. 4 is a view of enlarged scaleover FIG. 1 of the nut for securingthe cone member with respect to the form panel. 7 U

FIG. 5 is a sectional elevation of the cone member shown in the FIG. 2assembly, on an enlarged scale.

FIG. 6 is a perspective viewof a forming die used for establishing theoffset at the center of the tie rod shown in FIGS. 1 and 2. Y 1

FIG. 7 is an end view of the upper die member shown in FIG. 6, on areduced scale.

FIG. 8 is a side elevation of the die member shown on FIG. 7.

FIG. 9 is an end view of the lower die member shown in FIG. 6. 1

FIG. 10 is a side elevation of the die member shown in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, theopposite form systems 20 and 21 each include a panel as shown at 22 and23, respectively, reinforced by spaced vertical beams 24 and 25 commonlyreferred'to as studs." Spaced horizontal beams (walers) 26-27 bridgeacross the studs 24, and the beams 28 and 29 across the studs 25. Theforcetransfersystem maintaining the position of the form systems 20 and21 against the pressure of the poured concrete centers in the inner tierod 30 interconnecting the bolts 31 and 32. These bolts traverse theform systems-20 and .21, respectively, and receive the nuts 33 and 34bearing against the brackets 35 and 36. These brackets bridge across theassociated waler beams, and complete the transfer of restraining forces.The pressure of the concrete distributed across the inner faces of thepanels 22 and 23 generate large forces tending to separate the formsystems and 21, and these forces are resisted by the bearing pressure ofthe brackets 35 and 36 which are balanced out through the inner tie rod30. Tie systems of the type shown in FIG. 1 will be distributed aboutthe area of the form systems 20 and 21 with a spacing related to therelationship between the strength of the tie system and the concretepressure over the area which the particular tie system must resist.

The arrangement as described above is obviously capable of resisting theoutward pressures involved, and the remaining features are associatedwith the maintenance of the proper spacing between the panels 22 and 23.The tubular cone members 37 and 38 shown in FIG. 3 have a conicalsection 39 and a threaded tubular shank 40. The outside diameter of thisshank is sufficiently smaller than the major diameter of the conicalsection 39 to provide a shoulder 41 for bearing against the insidesurface of the associated form panel. The nuts 42 and 43 engage thethreaded shanks, and bear against the outer surfaces of the form panels22 and 23, respectively. The cone members 37 and 38, and also the nuts42 and 43 may be molded of a durable plastic material, as the stressestransferred through those members are relatively small. FIG. 4illustrates the preferred form of the nuts, which have a flange 44 todistribute pressures over a relatively large area of the form panels.The axial side flanges 45 (preferably on opposite sides of the nut)provide gripping surfaces so that these nuts can be tightened withoutthe use of a pipe wrench. The discontinuities 46 and 47 in the threadingon the shank 40 are preferably annular, and provide an indication of thecorrect tightened position of the nuts 42 and 43 for particularthicknesses of the plywood normally constituting the form panels 22 and23. The tightening of these nuts from the outside of the form is alsofacilitated by the provision of a non-circular crosssection in theinternal bore 48 of the cone members 37 and 38. A correspondingly shapedrod can be inserted as a wrench, making it possible to apply torque tothe cone member in opposition to the torque applied in tightening thenuts. Usually the cross-section 48 will approach a standard hexagonalconfiguration commonly associated with bolts and nuts. Tools of thisconfiguration are readily available.

The axial position of the bolts 31 and 32 in a direction transverse tothe form panels 22 and 23 is established (for properly erecting theform) by the cross pins 49 and 50 intersecting the holes 51 in theshanks of the cone members and a properly-located cross hole in thebolts 31 and 32. These pins may either be in the form of heavy nails, orof a hair pin-like configuration commonly associated with locking pins.Once these pins are inserted (after the attachment of the bolts 31 and32 to the inner tie the nuts 33 and 34 may be tightened lightly toestablish positively the spacing between the form panels 22 and 23, onthe assumption that the degree of threaded interengagement between theinner tie 30 and the bolts 31 and 32 has been carefully controlled. Withthe nuts 33 and 34 tightened lightly, the walers 26-27 and 28-29 areheld in place against the studs 24-25 without the use of extrafastenings. It will normally be desirable to nail the studs 24-25 to theassociated form panel's, but the usual practice of additionally nailingthe walers to the studs can be omitted. This not only resultsinincreased efficiency on the assembly of the forms, but makes itcorrespondingly easy to disassemble and remove them.

In the arrangement shown on FIG. 2, form systems 52 and 53 are similarto the form systems 20 and 21 of FIG. 1. The inner tie, the outer nuts,and the bearing members may also be identical to those shown in FIG. 1,but the cross hole for receiving the locating pin is not necessary inthe FIG. 2 system.

The cone members 56 and 57 shown in FIG. 5 have a conical portion 58similar to the portion 59 in FIG. 3. The shank 59 is only of sufficientlength to reach into or through the-associated form panel, and thethreaded portion 60 has an outside diameter interrelated with thediameter of the holein which the shank is inserted such that thethreading 60 bites into the material of the panel as it is screwed intoplace. A non-circular bore 61 traversing the tubular cone member 57receives a similarly-shaped tool to facilitate screwing the cone memberinto the position shown in FIG. 2. If desired, a shoulder on the bolts54 and 55 can be formed to bear on the inner ends of the. cone members56 and 57 to establish the spacing of the form systems. Alternatively, asuitably-shaped cross hole in the bolts 54 and 55 can receive a memberengaging either the studs or the walers to fix the axial position of thebolts with respect to the form systems for spacing purposes. Thesearrangements are well-known. In the arrangements shown in FIG. 1 andFIG. 2, the removal of the form systems leaves the cone members securedto the form panels, and the erection of the form systems in a newposition for the next pour is thus simplified.

The balancing of the pressure forces against the opposite form systemsby the inner tie 30 places rather severe requirements on this member.Efficient utilization of material requires that the rod stock of whichthe inner tie is made be heavily cold-worked to the point that the yieldstrength is approximately eighty percent of the ultimate. These membersloose their utility when substantial stretching takes place, and theyield strength is therefore the only usable strength characteristic. Theheavy degree of cold work produces a problem in providing the offset 62without generating a crack, or a point of weakness. The offset isnecessary to prevent rotation of the inner tie as the bolts aredisengaged, and also to prevent a breaking of the bond between thesurface of the tie and the surrounding concrete. The degree of theoffset 62 must be such as to strike a compromise between resistance torotation and any tendency to substantially weaken the tie.

FIGS. 6 through 10 show a die arrangement for producing the desiredoffset in a typical inner tie rod of the material described above. Forpurposes of illustration, this tie rod is of a material having anoriginal rod diameter of 0.272 inches, which is usually enlargedsomewhat at the threaded ends through the process of rolling thethreads. The upper die block 63 is shown in FIGS. 7 and 8, and producesa form of offset that has been found to be very satisfactory. The length65 and the height 66 may be selected to suit, but the dimensionextending in'the direction in which the rod is received in the die ispreferably 2.68 inches. This dimension is identified at 67 in FIG. 7.The V-shaped configuration primarily responsible for establishing theoffset 62 is shown in thecentral portion of FIG. 7 and the differencebetween the dimension 68 (0.17 inches) and 69 (0.06 inches) issufficient to control the spring-back of the rod stock. The radius 70 ispreferably 0.15 inches, and the radius 71 at the base of the groove 72is 0.31 inches. This is the radius that establishes the kink at the apexof the offset 62. The dimension 73 along the base of the V-shapedsection is preferably 0.68 inches, and the dimension 74 is one-half ofthis amount. The radius of the groove 72 is preferably 0.15inches forthe 0.272 rod stock, and the depth of this groove as shown in FIG. 8,identified at 75, is adequate at 0.02 inches.

The lower die member 64 is shown in detail in FIGS. 9 and 10. Thedimension 76, 77, and 78 are respectively 1.18, 1.87, and 3.06 inches.The dimension 79 and 80 are 0.09 and 1.53 inches. The radius 81 ispreferably 0.06 inches, and the radius 82 0.12 inches. The length andheight 83 and 84 shown in FIG. may be selected to suit.

Die blocks of the type shown in FIGS. 6 through 10 are normally placedin the conventional punch press, supported by the usual die-setassembly. The offset produced by these die members will deviate aboutone-half of the diameter of the rod from the axis of the rod, and willhave no substantial tendency to produce cracks or points of weakness.

I claim:

1. A method of erecting a wall-form panel assembly of the type having apair of form panels, external bracing for said panels, tie rodassemblies extending transversely across said panels and interconnectingsaid bracing, and a pair of tubular cone members associated with eachtie rod assembly, adapted to be secured to said panels and extendtherethrough, said tie rod assemblies being slidably received in saidcone members, comprising the steps of:

a. positioning said panels in spaced parallel relation to one another todefine opposite faces of a wall;

b. securing said tubular cone members to said panels;

c. inserting said tie rod assemblies through said panels and saidtubular cone members;

(1. fixedly securing said tie rod assemblies to said cone members toprevent relative movement of said panels and said tie rod assemblies;

e. erecting said external bracing on said panels; and

f. subsequently securing the ends of said tie rod assemblies to saidbracing in force transmitting rela-

1. A method of erecting a wall-form panel assembly of the type having apair of form panels, external bracing for said panels, tie rodassemblies extending transversely across said panels and interconnectingsaid bracing, and a pair of tubular cone members associated with eachtie rod assembly, adapted to be secured to said panels and extendtherethrough, said tie rod assemblies being slidably received in saidcone members, comprising the steps of: a. positioning said panels inspaced parallel relation to one another to define opposite faces of awall; b. securing said tubular cone members to said panels; c. insertingsaid tie rod assemblies through said panels and said tubular conemembers; d. fixedly securing said tie rod assemblies to said conemembers to prevent relative movement of said panels and said tie rodassemblies; e. erecting said external bracing on said panels; and f.subsequently securing the ends of said tie rod assemblies to saidbracing in force transmitting relation thereto.